This invention relates to a stable blood biochemistry control standard.
The determination of various blood serum components is now routine practice in the clinical diagnosis of disease. A wide variety of instruments has been developed for the rapid analysis of these blood serum components. Most of the instruments employ colorimetry and UV spectrophotometry as the means of the analysis.
In conjunction with the performance of the analytical tests made by these instruments, so-called biochemistry control standards are employed for control of the instrument to ensure constant standardization of the various biochemical determinations. Illustrative examples of such biochemistry control standards are those described in U.S. Pat. Nos. 3,466,249; 3,682,835; and 3,728,226. These prior art biochemistry control standards typically comprise aqueous blood serum, or freeze-dried serum which can be reconstituted with water before use, in which the serum has been treated by one means or another to provide certain desired properties.
Recently, new instruments have been developed which can utilize whole blood samples for analysis and are not limited to use of merely the blood serum fraction. When utilizing these instruments for biochemical determinations, the patient's blood samples need not be spun down to remove the cells and it is unnecessary to first wait for the plasma to clot before separating the serum therefrom. Thus, these instruments employ electrode systems which are not adversely affected by any blood cells present in the sample or even by hemolysis in the millieu surrounding the cells.
For use in the control of such instruments, it would be desirable to have a control standard which more nearly resembles the patient's whole blood, including the red cells, rather than the serum based biochemistry control standards of the prior art. Use of normal whole blood itself, of course, is too variable and unstable since normal red cells lyse and release enzymes, hemoglobin and K.sup.+ into the millieu.